1. Field of the Invention
The present invention relates to the sorting of timber, and more particularly to a method and apparatus for sorting timber by conveying it transversely on supporters of a sorting conveyor and turning the supporters to cause the timber pieces to drop from the supports into a sorting compartment or the like.
2. Description of the Prior Art
A conventional method of timber-sorting employs a chain conveyor on top of which timber is conveyed above sorting compartments. From the chain conveyor the timber pieces are, according to their type, dropped into various compartments. In known chain conveyors it is normal to use L-shaped supporters, for advancing the timber pieces, and the timber pieces are dropped by turning the supporters or an obstacle located in association with them, according to an address given to it above the sorting compartments.
The supporting parts of the conveyors are straight or may be turned upwards in order to prevent the timber pieces from dropping due to acceleration or decleration forces as the conveyor starts or stops. In spite of this feature, a drawback in the conveyors known so far has been that, as the sorting conveyor starts or stops, timber pieces that are slippery because of ice, for instance, do not remain on the supporters but fall prematurely from the same, thus giving rise to operating difficulties or causing timber pieces to enter the wrong compartments.
A drawback in the supporting parts of previously known sorting conveyors has also been that the dropping angle is the same were the timber pieces are broad or narrow. As the gliding distance of a broader timber piece is longer than the gliding distance of a narrower timber piece, the timing and placing of the drop become inaccurate even though a steep dropping angle is used.